In recent years, the optically assisted magnetic recording has been viewed with interest as a promising technique for next generation high intensity magnetic recording. In this optically assisted magnetic recording, a magnetic recording is performed with respect to a magnetic recording medium, which has high coercive force and high resistance against thermal fluctuations. Specifically, a light beam is focused on the surface of the magnetic recording medium to locally raise the temperature of the magnetic recording medium. At the heated portion of the magnetic recording medium, the coercive force is reduced, and thus a magnetic recording can be performed using a generally used magnetic head. To realize a still higher density magnetic recording, it is necessary to reduce the size of a focused light spot. In response, the technique of using near field, which permits a smaller focused light spot than a diffraction limit of light has been proposed. For example, Japanese unexamined patent application 2001-319365 (Tokukai 2001-319365; published on Nov. 16, 2001) discloses a technique that permits an optically assisted magnetic recording to be realized using the near field by providing a magnetic gap at a yoke extended section from a thin film transducer.
According to the foregoing conventional magnetic recording and reproducing using a magnetic gap at the yoke extended section from the thin film magnetic transducer, a problem of attenuation or delay of the magnetic field at the yoke extended section occurs, which hinders its application to a high frequency magnetic recording and reproducing.